Electric power apparatus for



ELECTRIC POWER APPARATUS FOR STEERING AND THE LIKE Original Filed June 1. 1949 June 30, 1953 w. F. PENROSE 2 Sheets-Sheet 1 NEYS & m m w.

WILLIAM F. PENROSE June 30, 1953 -w. F. PENROSE Re. 23,673

ELECTRIC POWER APPARATUS FOR STEERING AND THE LIKE Original FiledJune 1, 1949 2 Sheets-Sheet 2 INVENTOR. WILLIAM E PENROSE ATTOR YS Reissued June 30, 1953 s-motrmctrowsa Anranarusinom STEERING-AND THE-LIKE.

William Penrose, Birmingham, Mich.

Original No. 2587;3'77;

dated 5 February" 26; I952,

Serial @No. .96;559, June 1, 1949. .v Application. for: reissue September 23, 1952, Serial; No; =.Z,11,L'13

f Claims.

Matter. enclosed; iiuheavy brackets; [TI appears 111i; the original .2 patent but .forms'i no. partrofi'thisi reissue-specification; matterrprinted in italicsindicates theadditions madeby'reissum Thisinvention relates to electric; power; apparatus for steeringyand' the..-like.. More particularly, .itrelates. to animproved apparatus .offthe typein which the steering or other effort; is ef.'--

when. the. steeringfieffort exceeds. a predetermined amountl Another object is to.provide..an:apparatusof" the. character. describedlin which the. force ap plied by the booster. varies-.accordinggto 'the.steer.-- ing power. requirements as determined by the.op,-- erator.

Stilhanother object. is vto provide .an. apparatus of the character. described. in whichtthevpower;

booster can be coupled totoruncoupled.from'the steering; mechanism practically instantaneously, and in-which thepower-booster does nota-imposerany appreciable inertia effect upon the steering. mechanism.

A further objectais to provide ranx apparatus \ofthe character. described-which avoids ;oversteering by; thepowenbooster;

An r apparatus made according; to thea-invention comprises. a .manuallm rotatableshaftconnected:

through 1 a -.yie1dable coupling with. a. secondzshaft't to :berotated; the-coupling"being;yieldab1e:to ac-- commodate rotation. of. the -firsti shaft: inzeither's directionrelative to thersecond one.-. Associated with the second shafta areeelectromag netic.clutchs ing .means which; when energized. serveto clutch.

thesecond shaft-to anelectri-c motor so as toclr-ivei thesecond. shaft in1either. direction, depending:

upon thedirectionaof rotationotthei-first shaft. The. electromagnetic clutching. means. and. the.

electric motor are energized by: circuit meansin-v eluding; switch. contacts rota-table; with the two shaftsand interengageablewhen.the coupling between the shafts. yields. more... than.a predetermined. amountinresponse.to.rotation of the first The... electromagnetic shaft in. either. direction. clutchingmeansare energizedv through these. contacts andfalso througha variable. resistance, such: as acarbon pile, whichoperatesto decreasethe. circuit resistance. uponiincrease. in. the. pressure.

between the interengageable contacts. whereby the. clutching, effect. and. therefore. they power,

transmissionto; thesecondishaft increases with.

the torque. appliedimanually to thecfirst. shaft.

In the preferred" form of'th'e apparatus, the

second. or. drivenishaft. .is provided with two. ele'civ tromagnets rotatable .withthe shaft andijdisp'osedi.

adjacent. two.v gears rotatable. in. opposite direc;-

' tionsifrom the. electric motor; When the coupling.

between the shafts yields. more thana predeterr mined. amount upon rotation of the first shaft tric motor. and. a1so .one.of.' the. e1ectromagnetS,'-.

that is, theelectromagnetwhich.clutcheslthesem ondshaftto-the gear rotating.'in.the directionoff thefirstishaft, whereby. the second shaft is driven by the. motor.v in they direction of f the first shaiti so that the. contact onthe second'ishaft .willgtend to follow the.v interengaging;v contact. on: the first shaft. Any increase .in the pressure. between. the

contacts. due. to,v manual. rotation..- of. the. first;

l, 5 shaft atfi a. greater rate. than the second-shaft; operates on; a variable resistance. in. the. magnet.v circuit. to decrease the; circuit. resistance. and.

thereforeincrease the clutching effect so that.

thecontact'on thesecondlshaft will tend .to catch.

up. with theinterengag-ing contact on the first shaft. A'ssoon-asthe. rotation-.of'the first shaft is stopped,'.the.co.ntacts will" immediately. disengage. so .as tov unclutch the second shaft from the motor. When the. first shaft is, rotated inthe opposite direction,.. the other. electromagnet is *energizedithrough another set'ofcontacts. on the relatively movable. shafts, thereby clutching the second. shaft to. the motor. through. the other.

gear, .thatis the gear which is. now rotatinglin. thedirection of. thefirst shaft. Any increase. in I 5--the pressure. between thev contacts operatesv through. a variable resistor. in thecircuit-of the second magnet, to increase-the clutching;v efiect and therefore the. power. transmission to the sec-- ondishaft;

46" For abetter.understandingof the invention reference niay-be-hadtq the accompanyingdrawings, in. which Fig. 1: is-a..horizonta1sectional view, partly-in.

' ,plan, of. one-form of the new apparatusin-which "'the.circuits. are shown schematically;

Fig. 2.15 an enlarged sectional .view on line, 2--2 in Fig. 1;

Fig. 3 is a sideelevational .view of. one set .of the interengageable contactsv and... the variable 50"resistance in one of. the magnetcircuits; and- Fig. 4 is an enlarged elevational view'ofpar of the gearingt'of the apparatus.

Referring to. the drawings, the invention. as .there' illustrated is... in" an embodiment. suitable.

filiforuse as'a steering apparatus, such as asteer 3 ing apparatus for automobiles. The apparatus comprises a shaft I adapted to be rotated manually by the steering wheel (not shown), and a posed in an annular groove in thesteering'wheel shaft I and engages a wall of the housing so as to prevent outward movement of the shaft I.

A dog-clutch member 4 is keyed to the inner end portion of the steerin wheel shaft I, within the housing A, and is provided with'a pairof diametrically opposed lugs 4 A second dogclutch member 5 is keyed to the inner portion of the second shaft 2, within the housing A, and is provided at its inner end with diametrically opposed slots 5 for receiving the lugs 4 The slots 5 are sufficiently wide to receive the legs 4 with a substantial clearance, so as to permita limited rotation of shaft I relative to shaft 2. Reaction springs 6 and [5 engage the opposite sides of each lug 4 and are seated in recesses in the dog-clutch member 5. Thus, the lugs I and the opposin springs 6 and Ii form a yieldable, coupling between the shafts I and 2 for transmitting torque from the first shaft to the second shaft, the coupling springs being yield-v able to accommodate rotation of the first shaft in either direction relative to the second shaft.

Spring contact arms I and 1 are secured to the dog-clutch member I on the steering wheel shaft and are located in diametrically opposed relation on this member. The free or inner ends of the spring arms I and 1* carry electrical contacts II and H respectively, which are electrically insulated from the arms, as shown in Fig. 2.' Adjacent the respective contacts II and I l but normally spaced therefrom, are variable resistance units 8 and 8 which are mounted on the dog-clutch member 5 and therefore rotate with the second shaft 2. The variable resistors 8 and 8% are secured to the dog-clutch member 5 in diametrically opposed relation, as by means of insulated brackets 8'. As shown in Fig. 2, the resistor unit 8 is in the form of a carbon pile or stack of carbon discs 8| held between end plates 82 and 83 by the bracket 8*. The end plate 83, which is nearest the contact l I, is provided with a contact B4 engageable by contact II. The opposite end plate 82 is provided with a terminal 85 for connecting the variable resistance unit in a circuit to be described presently. The variable resistance unit 8 is constructed in the same manner as the unit 8. Variable resistors of this type are well known, and it will be understood that the resistance of the unit decreases as the carbon discs 8| are pressed together. In other words, the resistor 8, for example, will normally have a relatively high resistance, but when the contact II engages contact 84,, the electrical resistance of the unit 8 will decrease as the pressure between contacts II and 84 increases.

The dog-clutch member 5 also serves to carry a pair of electromagnets 9 and 9 disposed in axially spaced flanges 5 and 5, respectively, on this dog-clutch member. The magnets 9 and 9 serve as electromagnetic clutching means for clutching the shaft 2 to an electric motor I mounted in the housing A. The shaft of motor 4- IO carries a pinion II, and the latter drives a; pinion I2 mounted on a stud I2 on the housing. The pinion II meshes with a ear I3, and the pinion I2 meshes with a gear 14. The gear I3 is mounted loosely on an extension of the dogclutch member between the flanges 5 and the face of the electromagnet 9, whereby the gear'lfi is rotatable relative to the shaft 2. The gear as a is mounted loosely on the shaft 2 between the the spring contacts II II= with its corresponding 7 face of electromagnet 9 and one wall of the "nousing A, whereby the gear I4 is also rotatable relative to shaft 2. It will be apparent that when the electric motor I 0 is energized, the gears I3 and I4 will be'rotated in opposite directions from the'pinions I I and I2, respectively.

The motor Ill is adapted to be energized upon engagement of either of the spring contacts Ii, Il with its adjacent variable resistor 8 or 8 Assuming that contact II is moved into engagement with contact 84 of the resistor 3, the motor is energized from one side of a battery it through a wire H, a. brush I8 extending into housing A, a ring I9 on flange 5 wire 20, contacts II and 84, wire 2I connected to the resistor contact 84 (Fig. 2), ring 22 on flange 5, a brush 23 extending into the housing A, and a wire 25 extending to one side of the motor, the other side of the motor and the other side of the battery being grounded, as illustrated in Fig. 1. A branch 25 of the .wire 20 leads to the other spring contact 1 l and its coacting contact 84 of resistor unit 3 is connected bya wire 2I to the ring 22, so that the motor is also energized when the contact II engages the resistor unit 8*.

The electromagnet 9 is also energized upon engagement of spring contact II with its coastme contact of the resistor unit 8. That is, the terminal 85 of the unit 8 (the end of the resistor unit remote from contact 'II) is connected by a wire 26 to one side of the electromagnet 9, the

. other side of which is grounded, as shown in Fig.

1. Similarly, engagement of the other spring contact II with its coacting contact of the resistor unit 8 will energize the other electromagnet 9 through unit 8 and a wire 21 connected to one side of electromagnet 9 the other side being grounded, as shown in Fig. 1.

The operation of the apparatus is as follows: As long as the manual steering effort required to rotate shaft I is'small enough to prevent any substantial yielding of the reaction springs 6 and 5, the steering is effected entirely manually through the yieldable coupling 4 5, 6 and the shaft 2. However, when the necessary steering effort on shaft I becomes sufficient to engage either of resistor unit 8 or 8*, due to yielding of the coupling 4 6, 6, then the power booster is automatically brought into operation. Assuming that shaft I is rotated clockwise with sufficient force to compress the coupling springs Ii and engage contact II a with the adjacent resistor unit 8 the motor III will be immediately energized from the battery I8 through the brushes and rings I8, I9, 22 and 23, as previously described, so that the gears I3 and I4 are rotated in opposite directions. At the same time, the electromagnet 9 is energized from contact Il through the variable resistor 8 with the result that gear I4 is clutched to shaft 2 through the electromagnet net 9 tact H and the variable resistor 8.", the-resist:-

ance of the latter will, be relatively high, with the result that a. relatively weak clutching action will exist between electromagnet 9e and gear I4. However, this clutching action will become stronger as the pressure between contact H and resistor B increases, since the resistance of unit Ii will then decrease.

When the gear I4 is clutched to shaft 2 by en ergizing of electromagnet ,9, the shaft 2. is'driven from the motor in the same direction as shaft I, that is, clockwise. Therefore, the resistor unit 8 will be moved along a circular path (around the axis of shafts. I and 2.) in advance of. the contact I l and will remain in engagement with. the latter as long as the shaft I is rotated manually at a suflicient speed to maintain the interengagement. If the speed of the manual rotation ofshaft I is increased, the rotational speed of shaft 2 will, be increased. in the same direction and in a corresponding amount, by reason of: the resulting increase in the pressure exerted by spring contact Il upon the carbon pile of the variable resistor 8 and the consequent increase in the clutching effect by the gear I4 and electromag- When the rotation of shaft I is stopped or decreased sufiiciently to cause disengagement of contact H from resistor 8 the motor I0. and

I with sufficient force to compress the coupling springs 6 and engage contact H with its resistor unit 8, the motor Ill and the other ele-ctromagnet 9 are immediately energized, as previously described. The gear I3 will thenbe clutched to shaft 2 by the electromagnet 9, with a. force proportional t the pressure between contact "H and the resistor unit 8. As a result, the gear I3 will. drive shaft 2 in the same direction of rotation as shaft I (counterclockwise) so that the resistor unit 8 will be movedv in a circular path in advance of contact II and will remain in engagement with the latter until the manual rotation of shaft I is stopped or slowed down sufficiently to break the contact. As long as there is only slight pressure between contact II and resistor 8, there will will be considerable slippage between gear [3 and electromagnet 9, since the latter will then receive only a relatively small energizing current. As the pressure of contact II on resistor 8 increases, because of a, greater steering effort required by the operator, the gear I3 will be clutched more tightly to magnet 9 to effect a greater transmission of power to the shaft 2.

It will be understood from the above that the amount of power applied from motor It to shaft 2 is entirely dependent upon the turning force exerted upon the steering wheel shaft I by the operator. It will also be understood that the power applied from booster motor In to shaft 2 is not dependent upon speed of movement but can be applied in the required amount very slowly or very rapidly. The boost to the manual turning effort is stopped instantly by merely relaxing the turning pressure on the steering wheel. This relaxing of the turning effort causes an immediate declutching of the power train, and there is no resulting inertia on the manual steering by reason of the booster arrangement. The reaction springs 6, 6 can be made. of any desired strength to cause the booster to be brought intooperation at the desired point: and;

. 6 to: provide thedesired rate. of boost. ,They' can be made very strong.v so that the power boost is effected only at very high turning efforts, or they canv be made verylight so that the effort exerted by the operator would be mainly for controlling the mechanism, whereby he would do very little if. any of the actual work.

The new apparatus cannot cause overrunning .sistor units 8, '8. in a knob mechanism attached at some point on the rim of the steering wheel, and obtain the power cut-in and control by turning the steering wheel by the knob, so that when the steeringwheel is turned in the usual manner bytheirim there would be no power booster action. This would avoid cutting the steering shaft t provide the two aligned sections, and would eliminate the dog-clutch mechanism. It would also be possible to vary the speed of the motor I0 through the use of the variable resistors, and allow the. electromagnets to clutch the gearswith full force. In this way, an increased manual turning effort would cause more current to flow through the motor and thus create a more powerful boosting action, although with such an arrangement there would be slow speed and low power at light currents, while at high currents in the steering direction occurs, thereby resulting in a certain amount of oversteering.

If the motor-currents are too heavy to be handled directly by the switches at the variable resisters 8, 8 and the collector rings and brushes, they can be controlled by a solenoid starter similar to those used in automobiles for push button steering. If frequent starting and stopping of the motor Ill is not desired under certain con ditions, it is obvious that it can be energized continuously while the vehicle is in operation, since the motor is not in series with the clutches.

I claim:

1. An electric power apparatus for steering, and the like, which comprises a manually rotatable shaft, :1. second shaft to be rotated, a yicldablc coupling between the shafts for transmitting torque from the first shaft to the second shaft, the coupling being yieldable to accommodate rotation of the first shaft relative to the second shaft, an

electric motor, an electromagnetic clutch operable when energized to effect a driving connection be tween the motor and the second shaft, circuit means for energizing the motor and the clutch in separate circuits and including an electrical contact on the second shaft, and an electrical contact rotatable with the first shaft and en gageable with the other contact, upon yielding of said. coupling, and a variable resistor in circuit with said contacts and located in the separate circuit through. the clutch, said resistor being operable upon increase of pressure between-said contacts to decrease the resistance in the clutch circuit independently of the motor circuit.

2. An electric power apparatus for steering, and the like, which comprises a manually rotatable shaft, a second shaft to be rotated, a yieldable coupling between the shafts for transmitting torque from the first shaft to thesecond shaft, the coupling being yieldable to accommodate rotation of the first shaft relative'to the second shaft, an electric motor, a pair ofgears rotatable by the motor in opposite directions, a pair of electromagnets rotatable with the second shaft, one magnet being disposed adjacent one of the gears and the other magnet being disposed adjacent the other gear, each magnet being operable when en ergized to clutch the adjacent gear to the second shaft, an energizing circuit for one of the magnets including electrical contacts rotatable with the shafts and interengageable upon yielding of the coupling by rotation of the first shaft in one direction, an energizing circuit for the other magnet including electrical contacts rotatable with the shafts and'interengageable upon yielding of the coupling'by rotation of the first shaft in the opposite direction, means for energizing the motor upon energizing of either of said circuits, and a variable resistance in each magnet circuit and operable to decrease the circuit resistance upon increase in the pressure between the interengaging contacts in the circuit, to increase the clutching effect between the corresponding magcoupling between the shafts for transmitting torque from the first shaft to the second shaft, the coupling being yieldable to accommodate ro- .tation of the first shaft relative to the second shaft, an electric motor, a pair of electromagnet's each operable when energized to clutch the motor to the second shaft, the second shaft being ro-.

tatable in opposite directions by the respective magnets, a pair of switching contacts in circuit with the motor and one of the electromagnets and operable by rotation of the first shaft in one direction relative to the second shaft, a second pair of switching contacts in circuit with the motor and the other electromagnet and operable by rotation of the first shaft in the oppositedirection relative to the second shaft, and a variable resistor in circuit with each pair of contacts and each electromagnet and operable by increased pressure between the contacts to decrease the resistance of the circuit through the corresponding electromagnet.

5. In combination, a rotatable shaft, a second shaft to be driven, the first shaft being rotatable in either direction relative to the second shaft, an electrically operated power booster including electromagnetic clutching means for rotating the second shaft in either direction, a circuit for ener gizing the clutching means to drive the second shaft in one direction and including contacts engageable by rotation of the first shaft in said direction relative to the second shaft, a second circuit for energizing the clutching means to drive the second shaft in the opposite direction and ineluding contacts engageable by rotation of the first shaft in said opposite direction relative to the second shaft, and means included in said circuits for increasing the energizing of the clutching means with increase in pressure between said contacts.

6. A combination according to claim 5, in which said means for increasing the energizing of the clutching means include a variable resistor operable by increase in pressure between the contacts.

7. A combination according to claim 5, in which said means for increasing the energizingof the clutching means include a variable resistor in each circuit and operable by increase in pressure between the contacts to decrease the circuit resistance.

8. In combination, a rotatable shaft, a second shaft to be driven, the first shaft being rotatable in either direction relative to the second shaft, a power source including electromagnetic clutching means for rotating the second shaft in either direction, a first circuit for energizing the clutching means to drive the second shaft in one direction, circuit control means located in and controlling said first circuit and including a movable pressure applying means connected with and actuated by rotation of the first shaft in said one direction relative to the second shaft, a secand circuit for energizing the clutching means to drive the second shaft in the opposite direction, circuit control means located in and controlling said second circuit and including a movable pressure applying means connected with and actuated by rotation of the first shaft in said opposite direction relative to the second shaft, and pressure responsive means included in the clutch energizing circuits in cooperative relation to said pressure applying means for increasing the energizingof the clutching means in response to increased pressure applied to said pressure responsive means by said pressure applying means.

9. A power apparatus for steering and the like which comprises a manually rotatable shaft, a second shaft to be rotated, a yieldable coupling between the shafts for transmitting torque from the first shaft to the second shaft, the coupling being yieldable'to accommodate rotation of the first shaft relative to the second shaft, a rotatable power means including electromagnetic clutching means for rotating the second shaft in either direction, a circuit for energizing the clutching means to drive the second shaft in one direction and including contacts engageable by rotation of the first shaft in said direction relative to the second shaft, a second circuit for energizing the clutching means to drive the second shaft in the opposite direction and including contacts engageable by rotation of the first shaft in said opposite direction relative to the second shaft, and means included in the clutch energizing circuits for increasing the energizing of the clutching means with increase in pressure between said contacts.

10. In combination, a first shaft comprising a steerlngwheel shaft manually rotatable in either direction, a second shaft to be driven and being rotatable in either direction, means defining a flexible substantially direct torque transmitting connection between said first shaft and said second shaft for rotation of the latter in either direction by the manual rotation of the former, a unidirectional rotatable power means, two gear trains connecting said second shaft with said power means for rotation of said second shaft in either direction by said power means and including electromagnetic clutching means comprising I an electromagnetic clutch in each of said gear trains, circuit means for energizing one of said electromagnetic clutches to drive the second shaft in one direction and including circuit control means actuated by rotation of the first shaft in said one direction relative to the second shaft, circuit means for energizing the other of said electromagnetic clutches to drive the second shaft in the opposite direction and including circuit control means actuated by rotation of the first shaft in said opposite direction relative to the second shaft, and means included in said circuit means for increasing the energization of the energized electromagnetic clutch in response to increased pressure applied to the circuit control clutch.

WILLIAM F. PENROSE.

or the original patent UNITED STATES PATENTS 5 Number Number 

